Nantucket Forests - Short Trees and Short Timbers

Short Trees and Short Timbers

Nantucket Island lies 30 miles off the southern coastline of Cape Cod, Massachusetts. In 1775, Nantucket was the largest whaling port in the world, and the third largest port in Massachusetts. However, dominance in this most adventurous, dangerous and potentially lucrative of all maritime trades was not supported by an extensive, local, ship building industry. Early Nantucket forests were unusual and determined the scope of indigenous and colonial wooden ship building on Nantucket Island.

In spite of numerous statements about island forests as a source for lumber (see 1889 USGS report which only repeats local oral tradition), a strong case can be made that Nantucket has not been forested for the past 4,000 years at least in terms of what is usually thought of as a forest - numerous tall trees 50 or more feet in height. Visitors to Nantucket in the late 18th and early 19th centuries describe the island as nearly treeless. However, many publications mention post glacial forests composed of oak, with some beech, pine, maple, and hickory. These trees were present but only in small numbers and severely reduced in height. They were cut down for firewood, fence posts and short building timbers in the decades following settlement in 1659. Speculation that after the island trees were cut down, a rich soil was washed away by erosion cannot be confirmed. Nantucket has many small dry' valleys without outlets to the sea, and rich loam soil cannot be found in these localities. Old forests have not existed for the past 2,000 years or more, deep rich leaf mold is absent and adequate soil depth to provide root anchorage for large trees is not present. This photograph of a contemporary Nantucket moor depicts a landscape with few trees none of which are very tall, nor do they have straight trunks from which long timbers for shipbuilding or house construction could be made. These particulars make a relevant reference to the history of Nantucket forests.

Oak building timber for houses and ships could not have been produced from island trees. Nantucket Island is a low altitude, sand dune environment with numerous ancient peat bogs and continual winds that are salt saturated. The highest points on Nantucket Island island are Folger Hill at 109 feet above sea level, and Altar Rock at 108 feet. In the mid 20th century, only two small strips of good loam could be identified on the island, and both were shallow. Evidence indicates that the last tall forest trees on Nantucket died at least 2,000 years ago, portions of their trunks have been preserved in ancient peat bogs. These are remains of tree trunks whose maximum diameters were 12' and trunk height was only a few feet above ground, Trees of 20–25 feet tall are indicated, a height that can rarely be exceeded because of continual exposure to blowing, salt saturated wind. Tree trunk remains found in these ancient peat bogs belong to the only three species that can survive long exposure in such environments: cypress, red cedar and white cedar. These tree species require fresh water, they no longer grow on Nantucket and were never available nor appropriate for long building or ship timbers. Frequent exposure to high winds and blowing salt severely restricts the maximum possible height for both hardwood and coniferous tree species. A storm with salt saturated, winds of 60–80 mph will tear apart the top branches of a tree. Blowing salt also adheres to bark and leaves and relentlessly penetrates the wood to induce rot and tissue death. Trees in more protected sites, are more than a few tall. Nonetheless, they are forced into a distorted growth pattern by the relentless, salt saturated wind. Maximum height is severely reduced, and their profile is very distinctive as seen in Theodore Robinson's painting done in 1882.

"On Nantucket, oak, pine and beech can attain heights of only a few feet, albeit with distorted trunks whose width would suggest a tall tree of the usual height. A typical black oak (Quercus_velutina) so formed, might have a 20" trunk diameter but a morphology that is severely restricted by 'wind pruning' and thereby less than one foot tall with branches buried or growing along the ground; or alternatively, many feet wide at the base but less than two feet in height to the fork in the trunk where branches form. Cedar roots can spread and coalesce on the ground creating a large mass of wood that has almost no height and is not a tree trunk. Low hills on the north east sector of the island afforded protection from severe wind pruning in the past but severe Erosion since 1896 has greatly reduced the altitude of these hills. In some protected niches, oak and beech trees did grow to 20–25 feet tall and were often cut when about 50 years of age for fence posts and firewood. A period of intense cutting of the remaining oak and beech trees of this size and age has been identified in the late 19th century.

A consistent exception to this dwarfing of tree species is the Japanese Black Pine. It had evolved in an environment nearly identical to that of Nantucket, and was introduced in the late 19th century . Pitch pine will also achieve some height in highly acidic soils but was likely nonexistent on Nantucket prior to 1847 when introduced to be used in windbreaks. "Small patches of dry upland soils within these forests contain some beautiful, old examples of American beech, black oak, white oak, and American holly, trees that are now relatively rare on Nantucket."

The photographs in this article portray a selection of swamps and bogs whose characteristics resemble those reconstructed for the ancient swamplands on Nantucket. They are a best effort at depicting what the ancient swamps, bogs and adjoining forest trees might have look liked on Nantucket more than 2,000 years ago.

• Bog tree stump, Scotland

• Acushnet Swamp, Massachusetts

• Acushnet Cedar Swamp, Massachusetts

• Hawley Bog, Massachusetts

• Spruce Hole Bog, New Hampshire

• Heath Pond Bog, New Hampshire